How is Verizon's iPhone 4 different from AT&T's?
In terms of hardware, Verizon will have almost the exact same device. The major difference is the CDMA chips inside the Verizon iPhone that will allow it to run on Verizon's network. On the outside, the most eagle-eyed observers will notice that the Verizon iPhone 4's ringer/mute switch on the top left side has been moved slightly downward. Apple says it was done to accommodate the CDMA chips on the inside, and consequently iPhone 4 cases and bumpers currently on the market will not fit correctly.

The Verizon iPhone's software is slightly more advanced too: it's running iOS 4.2.5, while the most current release for all other iPhones is iOS 4.2.1.

In terms of wireless service, CDMA technology currently does not allow voice and data to be sent over the network simultaneously, which means you can't, for example, make a phone call while checking e-mail or using the maps app. The CDMA Development Group has said this capability will be available to all CDMA operators sometime this spring.

How much will the Verizon iPhone cost?
Verizon is offering the iPhone 4 for the same price as Apple, AT&T, and others: $199 for 16GB, $299 for 32GB. Both include a two-year contract.

We don't know much about pricing on plans just yet. Verizon COO Lowell McAdam said at Monday's press event that he wasn't ready to give details.

When can I buy it?
If you're a current Verizon customer, congrats, you get first crack at it. You can pre-order it starting February 3. The rest of us have to wait until February 10 for the official launch.

Will I finally be able to buy a white iPhone 4 then?
The answer is no, for now. A Verizon representative told CNET a white iPhone 4 will not be available next month. The official line from Apple remains in effect: the white model will be available sometime this spring. (Here's additional background on the saga of the white iPhone 4.)

What's the Verizon iPhone's SAR?
The iPhone 4 on Verizon has a SAR (specific absorption rate) of 1.18. The iPhone 4 on AT&T has a SAR of 1.17. Since the difference is so small, it's basically the same.

A cell phone's SAR is a measure of the amount of radio frequency (RF) energy absorbed by the body when using the handset. All cell phones emit RF energy, and the SAR varies by handset model, even if it's the same phone across different carriers.

Is Verizon the only one who can sell a CDMA iPhone?
Nope. Apple COO Tim Cook told reporters today that while Apple and Verizon have a "multiyear" contract, it is not exclusive. That means other CDMA carriers like Sprint could potentially be next to sell the iPhone.

Verizon's Lowell McAdam (left) and Apple's Tim Cook seal the deal on the first iPhone to be offered by Verizon.
Sarah Tew

If Verizon is pushing its LTE network so hard, why is the iPhone still on CDMA?
Apple's Tim Cook said there were two main reasons that the iPhone isn't on LTE: the first generation of LTE chipsets "forced design compromises," and "Verizon customers want the iPhone now."

Can I use my existing AT&T iPhone 4 on Verizon's network?
Unfortunately, the iPhone 4 that is designed for and sold by AT&T will not work on Verizon Wireless' network. The reason is that the AT&T iPhone is based on a technology standard known as GSM, while Verizon Wireless uses a technology standard called CDMA. These are different technologies, and they are not interchangeable. So if you want to use the iPhone on Verizon, you'll have to purchase the new CDMA iPhone 4 designed specifically for Verizon Wireless.

If I want to switch carriers, should I cancel my current contract?
Don't even think about it! The best way to lose your cell phone number forever is to cancel your contract with your current carrier (AT&T, Sprint, T-Mobile, or others) before signing on to a new one. Instead, walk into any Verizon retail store with your current phone in hand and sign up for a new contract. Verizon reps will do all the heavy lifting for you.

Will I need to sign a new contract?
Yes, unless you wish to buy the iPhone 4 at the no-contract price, which typically costs much more up front. Again, the 16GB model will cost $199 with a two-year contract; the 32GB model will sell for $299.

How long will it take to port my number?
The timing varies, but you could get use of your number on your new phone in as few as three hours, or up to a day. If the volume of requests is too high, the port could take as many as four days. Patience is a must.

What do I do to activate the porting?
You won't have to do a thing. When the porting is complete, you'll receive a text to your new phone. The porting process is identical from all carriers.

Will I be charged extra fees to switch from AT&T to Verizon?
There is typically an activation fee for new two-year contracts. In addition, you're responsible for paying your previous carrier for the final service charge before you canceled. If you duck out of a contract, you'll also face an early termination fee (ETF).

If you bought your iPhone after June 1, 2010 you will be subject to at most a $325 early termination fee. AT&T prorates its ETFs, so that penalty is reduced by $10 for each full month you complete of your service.

Do you think that there will be a mass exodus from AT&T's network to Verizon's network for the iPhone 4?
I have no way to predict the future, but I don't think that there will be a mass exodus from AT&T to Verizon Wireless. While there is significant pent-up demand for the Verizon iPhone, I think that most of the initial customers will be existing Verizon customers. These are likely people who are loyal Verizon subscribers.

There are also lots of subscribers who abandoned Verizon for AT&T to get the iPhone. There is a good chance that Verizon will win some of these customers back. And Verizon could also win customers from Sprint Nextel and T-Mobile USA--those who wanted the iPhone but were unwilling to go to AT&T because of the network issues.

But given the fact that the Verizon iPhone is essentially the same phone that has been offered by AT&T since June 2010, I don't think that existing AT&T customers who are moderately satisfied with the AT&T service will jump ship yet. For one, a good portion of these customers, especially those who just bought the iPhone 4, are still under contract.

What do you think AT&T will do to compete with Verizon? Will it reduce data service prices?
It's too early to say if AT&T will launch a price war to retain customers and to win new ones. Verizon hasn't announced its data plan pricing yet for the iPhone, but if it chooses to price the service more aggressively, AT&T may be forced to respond. This means that AT&T may offer a cheaper service plan to compete. Or AT&T may end up reinstating an unlimited-data plan, if Verizon decides to keep its own for iPhones. AT&T eliminated its unlimited-data plan in June for new customers, replacing it with a tiered-service offering.

A price war between AT&T and Verizon would be great news for consumers.

The new competition for the iPhone is also likely to put even more pressure on AT&T to improve its network. Now that the iPhone is also on Verizon, AT&T's biggest rival, AT&T will need to find new ways to compete more aggressively with Verizon. AT&T is improving its network, but just how quickly it can add capacity and improve reliability is crucial, as it competes head to head with Verizon.

Again, this level of competition is great news for consumers because they will likely see continued improvement in AT&T's network performance.

Do you think that Verizon's network will be able to handle all the new iPhone subscribers?
Verizon's executives say they are ready for the iPhone. Verizon Wireless CEO Daniel Mead said during the presentation Tuesday that Verizon has been working with Apple since 2008 to develop an iPhone for its network. He said the network has been tested, and he is confident that consumers will continue to have the same reliable service with the Verizon iPhone that they have come to expect with other Verizon devices.

"I feel very confident about our 3G and 4G networks," he said. "We have seen tremendous growth over the past 18 months on our network with the Android devices and other smartphones. We are adding more capacity to the 3G network in 2011 to meet whatever demands customers put on us."

What will this mean for Google Android phone manufacturers? Are they screwed?
There is no doubt that the Verizon iPhone will be stiff competition for Google Android phones. Verizon is the strongest sales channel in the United States for Android devices. And it has especially close ties to Motorola, which launched its Droid exclusively on Verizon's network.

Android phones at Verizon were marketed as alternatives to the iPhone. But now that the iPhone is on Verizon, these manufacturers and Verizon will have to find new ways to differentiate the Android products and position them with respect to the iPhone. This could be a big challenge, given the strong brand recognition and loyalty to the iPhone.

That said, Verizon showed last week at CES that it is still very much behind the Android platform. It launched 10 new products at the trade show, all of which are based on Google Android software. These new devices will be the flagship products for the new 4G LTE network that Verizon launched in December.

Apple has introduced a new iPhone in the summer every year since 2007. Do you think that it will announce another iPhone this June? And will the GSM iPhone for AT&T offer anything the CDMA iPhone on Verizon won't have?
In the past, Apple has released a new iPhone every year. So I would imagine that it will also be releasing a new version of the product in early summer, as usual. Again, I don't have a crystal ball, so I don't know for certain what the company will do. But my guess is that Apple will release an HSPA+ version of the iPhone for AT&T. This version, which AT&T will likely market as 4G, will be faster than the current AT&T or Verizon iPhone 4 phones. HSPA+ is the next evolution in the 3G standard for GSM networks. It has the potential to offer much faster download speeds, but it may not be as fast as LTE.

When will a 4G LTE version of the iPhone be on the market?
That's a good question. Again, this is just a guess. But based on what Apple has done in the past, I think that it will be at least a year before Apple puts LTE chips in any iPhones, regardless of whether they are made for AT&T or Verizon. (AT&T is launching its LTE network this summer. And Verizon launched its LTE network in December.)

I think that Apple will wait until the LTE chip market is more mature before it puts them in iPhones. There are two reasons for this. First, the cost of those chips will drop considerably over time and will reduce the cost of producing the devices. And second, I think that Apple also wants to wait until all the kinks on LTE devices have been worked out. I expect LTE smartphones to have some battery life challenges. Apple is all about creating the best overall experience for consumers, and that requires a satisfactory battery life.

As you may recall, the very first iPhone worked on AT&T's 2.5G EDGE network, even though there were already plenty of 3G handsets on the market. It took Apple another year before it introduced the iPhone 3G.